Study Room 221B, Hogwarts North Tower
by Sano S. Sagara
Summary: John is a survivor of the Battle of Hogwarts, and returning for his Fourth Year at Hogwarts. Sherlock is a brilliant yet frustrating First Year. The two strike up an unlikely friendship over talking skulls, oddly shaped patronuses, and running their Prefect friends ragged. Includes all major characters, but may not follow cannon storyline.
1. Chapter 1

**A/N- Hey there! If you missed it, Children of the Sun and Moon also updated!  
This story here is based off of a great bit of artwork for Sherlock going around where Sherlock and John are members of the DADA club and Sherlock is having trouble conjuring his Partronus. John suggests he needs a different happy memory, and Sherlock thinks about them meeting on the train to Hogwarts. I thought I would expand that idea a bit, so here comes this fairly short chapter-the first of a few fairly short chapters of a fairly short story. But hey, I liked the idea ^_^. **

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As John limped down the aisle of the Hogwarts Express he passed compartment after compartment filled with loud, excited students. He smiled to the ones he knew, and nodded to the odd polite wave from random first years. He could almost see them quivering, and a few that had to be muggle born looked positively green around the gills. Ahead of him a compartment opened and John saw his year mate Mike Stanford back out.

"Oye!" John waved, pulling his trunk along behind him and trying to limp a bit faster, "Mike!"

Mike was a Hufflepuff to John's Gryffindor, both of them Fourth Years. They'd taken Medical Charms together last year, and had bonded over a mutual love of muggle sports-slow that they were.

"John! So, Gryffindor _still_ hasn't kicked you out yet?" Mike reached forward to grasp forearms with John, while casting an odd little glance back to the compartment.

"No, I don't think they're planning on it either. Though, I suppose I can always count on Hufflepuff taking me in!"

"We're good Finders, John, not good Martyrs. Why aren't you settled in somewhere with your nose stuffed into Madam Pomfrey's text book?"

"I can't find an empty compartment. It's like everyone's been chewing talky-taffy. John shrugged and peered around Mike when his friend's gaze shifted back to the door, "There anyone in there?"

"Um, just a new first year-Sherlock Holmes. Perhaps you know his older brother Mycroft? He's a Ravenclaw Prefect,"

"Can't say I do," John followed Mike to the door and peered inside the compartment, where he saw the tallest first year he'd ever come across. The boy had masses of dark curly hair that looked like he frequently yanked at it. Cradled in his long fingered hands was a scull of some sort which he absentmindedly petted.

"Cor, he's tall," John blinked when the younger boy looked up with the most startling pair of glaz eyes he'd ever seen and leveled him with a cool stare.

"Wanna meet him?" Mike asked it like he knew some sweet joke, but John has already shouldered his way into the compartment.

"Hi, I'm John Watson," John's grin faded and his outstretched hand fell as Sherlock just stared at him. The boy turned to Mike, "Mike, may I use your wand a moment?"

John almost flinched. Someone's wand was a highly personal thing, but here was Mike, one of the most cautious Hufflepuffs he knew, patting his pockets for his wand. Grimacing, he said,

"Sorry Sherlock, I left it locked in my compartment,"

Sherlock sighed and tapped mournfully at the skull.

John glanced at Mike, surprised to meet his friend's eyes, and even more surprised when Mike nodded at Sherlock, urging John on, "Er… Here, use mine," John pulled his wand from his pocket, first brandishing it, then expertly flipping it to offer it to Sherlock by the well-worn grip.

Sherlock's eyes travelled slowly up the length of wood, then even more slowly up John's arm and to his face, studying John again like he was revising an opinions.

"Thank you," Sherlock wrapped his long fingers around the wand and hefted it, twirling it a moment before tapping the skull and whispering an incantation too low for either Mike or John to hear. John accepted his wand back as the three stared expectantly at the skull.

"Ash, surprisingly rigid for Dragon Heart's string, don't you think?" Sherlock's quiet voice made John jump.

"How… how did you know that?"

The skull in Sherlock's hands twisted around to fix hollow eye sockets on John, and in Sherlock's voice replied, "The same way he knows you fought for Dumbledor's Army, and that you have a psychosomatic limp from The Battle, and that you play Keeper on the Gryffindor team, and that your brother's an alcoholic,"

John and Mike stared in stunned silence as the skull rocked in Sherlock's loose grip and turned back to face the now triumphantly smirking first year.

"Finally got that spell to work?" Mike managed, just as John surged forward excitedly.

"This is-," John reached forward and Sherlock flinched, but John missed it as he gently took the skull from him, "_Fantastic_!"

Sherlock's head snapped up and the skull's jaw fell open with a clatter, "That's not what people normally say," commented the skull, sounding shocked.

John smiled at Sherlock, then asked the skull, "And what do they normally say?"

But the skull burrowed its face in his palm and declined to answer.

"…piss off," Sherlock murmured as he accepted his skull back from John. The unsure expression on the boy's face morphed into a small but genuine shy smile as John laughed.

"Well I think that is fantastic. How'd you do it? I was never good at charms like that,"

Neither boy noticed when Mike slipped away, leaving John to badger Sherlock with questions. The younger boy traded answering with his skull. The rest of the train ride found them locked in conversation as Sherlock explained to John how the feel of his wand told him the core was Dragon Heartstring, and the bit of odd discoloration on the ash showed that the most used spell was a hangover cure. Sherlock told him that the way he moved and appraised his surroundings, as well as his age, had tipped him off that he'd been a part of the Battle, and that the callouses on his hands from his broomstick betrayed his position as Keeper.

John's anatomy text lay forgotten atop his trunk as he listened to Sherlock talk. When the train pulled up to the Hogwarts platform, John leaned over to Sherlock,

"You did get one thing wrong about me, though," John laughed as Sherlock hounded him all the way from the compartment to the Thestral-drawn carriages.

At Sherlock's sudden silence, John turned with a sad smile, "I'm sorry, I didn't think… Maybe you wouldn't have been able to see them,"

Sherlock frowned at John's sentiment, "No matter. Now, tell me!"

John just laughed and climbed into his carriage with Mike and Gryffindor second year named Molly Hooper. Turning as they clattered away down the bridge, John laughed again to see Hagrid trying to drag a fuming Sherlock toward the first year's boats.


	2. Chapter 2

Sherlock was furious. He glared daggers at the floor of his boat the entire trip across the lake. What had he gotten wrong?

His desperate rethinking of each detail of his and John's encounter preoccupied him until he joined the throng of new students waiting breathlessly outside the doors to the Great Hall. The smell of fantastic food filtered out to make his stomach growl. Surprised, Sherlock looked down, annoyed at the involuntary reaction to hunger. He looked around, distracting himself, and his eyes fell on a short girl with thin, mousey brown hair and milky skin with a smattering of freckles. She looked no more able to withstand a gust of wind that the slightest strand of spider's silk, but the stubborn set of her jaw below her shyly downcast eyes told Sherlock she would be a Gryffindor rather than Hufflepuff.

One by one his eyes flicked over the other first years around him, marking them out for the houses the Sorting Hat would undoubtedly place them into. The boy with flaming red hair and a hard mouth a Ravenclaw, the sweet looking blond next to him with her steel grey eyes would be a Slytherin. Three future Hufflepuffs stood together, leaning against each other for comfort even as they vibrated with excitement. Two very tall girls, twins, were standing with their hands just touching. One would be a Gryffindor. The other Slytherin. It would cause a rift between them that would soon be healed by their short male friend with long black hair. He would be a Ravenclaw as well, what with the stack of pristine books strapped neatly under his arm.

Sherlock twisted to look behind him, and felt the hair raise on the back of his neck. A short, dark haired boy stood at the very back of the group, his robes perfect, spotless. Hair combed neatly. Skin sallow, dark circles under his eyes. Eyes that were wide and rolling like a spooked horse. And a gash of a grin with harsh with teeth visible all the way to the gums.

Sherlock almost stepped back when that crazed gaze landed on him. Eyes locked, and Sherlock saw the boy's entire body vibrate, then still. His expression blinked out in a second, face schooled to a perfectly blank canvas, politely disinterested and bland. Only the dark circles under those dark eyes stayed, and Sherlock swallowed, unwilling to break eye contact first. The boy smiled at him, slow, long, the crooked line of his lips curling into a snarl as much as it was a smile. It wasn't inviting, it was threatening. It was challenging.

It was insane.

The doors to the Great Hall flew open and Sherlock was jostled by a group of girls bouncing excitedly, and when he looked back, the dark haired boy was already gone.

One by one the first years subjected themselves to the Sorting Hat's judgment, and by the time Sherlock's name was called he'd only guessed wrong twice. One was a large hulking boy who slinked his way bashfully over to the Hufflepuff table, and another was a pixie faced girl with pink ribbons in her hair that walked to the Slytherin table with her nose in the air and a stiff posture.

Sherlock peered out at the hall from under the fringe of his bangs while Professor McGonagall gently lowered the Sorting Hat onto his head. There was John, sitting at a Gryffindor table nearest the Ravenclaws, leaning back in his seat to get a clear view of the new first years, grinning widely. When the blond saw Sherlock looking, he waved and grinned cheekily.

Sherlock felt his lips twitch in a tiny smile before the dusty voice of the Sorting Hat filled his mind.

'Child… what are you doing here?'

'What a stupid question,' Sherlock scrunched his nose, 'I'm here to go to school,'

'No… you could teach yourself everything in all the books in these walls,' it sounded like the Hat was taunting him.

'I already have,'

Sherlock wasn't ready for the laugh that erupted from the brim above his ears, and yelped a bit, 'I don't see what is so funny,'

'You are, little child. Very well, welcome. Welcome to Hogwarts. I think you're going to find what you're looking for here,'

About to ask what the Hat meant, Sherlock was cut off when it bellowed out "Ravenclaw!" and he was ushered amongst the obligatory cheering to his table. He might have taken a slightly less direct path to the nearest open seat so he could pass by John, but as the older boy gripped his arm quickly in congratulation, he wouldn't have admitted it.

The Next Day

Come Potions, Sherlock was already desperately bored. He'd known all the beginning material in all of his classes so far-Herbology, Arithmancy, Charms-and while he'd memorized his potions text book, at least potions required more than just knowledge by rote. It also needed skill and intuitive experimenting, and Sherlock found himself actually looking forward to correcting the recipes in his text book. He pulled out his book and flipped to a particularly oddly proportioned potion and pretended to be studying until his professor came in, and settled comfortably onto a bench a little ways away from the other Ravenclaws.

A thump and the sudden appearance of a boy next to him startled Sherlock from his fake concentration, and he looked up into John Watson's widely grinning face.

"Sherlock! What a surprise!" Sherlock studied the older boy with a furrowed brow.

"Why are you here John? Surely you cannot be so dismal a student as to be attending first year courses…"

"Ah-ah," John wagged a finger at him, "That's Assistant Professor Watson, to you Sherlock. At least in here," Sherlock blinked for a moment before sighing heavily,

"And here I thought I would be learning something," secretly, Sherlock was pleased that John was intelligent enough to warrant an assistant teaching position in the school.

John sneered good naturedly at Sherlock, and made his way to the blackboard to stand next to Professor Slughorn, who stepped aside with a stern look to the murmuring students.

In the hush, John cleared his throat, "Hi, I'm Assistant Professor John Watson. I'll be teaching a special section of Medical Potions this semester. If you want to transfer to a normal Potions course, I won't be offended, but take my word for it, this will be interesting-,"

"And useful, if the last few years of students have been any indication!" Slughorn chortled.

John smiled back, "Yes, useful to boot. If you find you want to take a complete course, I'll be teaching Medical Potions if you have a free period you want to fill up. I suppose that's it, I hope you all enjoy this experiment," John walked back to his seat next to Sherlock, grinning just a bit smugly at the impressed look on Sherlock's face.

As Slughorn began to drone on about how to perfectly make a wit-sharpening potion, Sherlock let his mind wander. It came back frequently to wonder about John's Medical Potion course. It seemed interesting, and certainly useful. He'd lost count of all the times he'd had to blunder through a splinting spell after one of his experiments had gone wrong. His eyes flicked to study John himself. Neatly pressed muggle clothes under immaculately kept school robes. His wand, his bag, his quills were all old, but well maintained. His feet were neatly shod in worn brown leather shoes, scuffed but freshly polished. His books were pristine, but bristling with scraps of parchment with colored tabs at the tips. Sherlock realized John was self-sufficient, perhaps even living on his own, but he wasn't lacking in money. The older boy just appeared to live frugally.

John leaned over and flicked the end of his long nose with the feathered end of his quill, "Pay attention, little Ravenclaw!" he chided, and Sherlock leveled him with a withering glare before pulling his parchment closer and taking redundant notes. As his quill scribbled on autopilot, Sherlock listened with one ear as John muttered mutinously to himself.

"Not enough armadillo bile…" John made a scratchy note, then crossed it out and rewrote it as "dilute with pygmy puff saliva, more stable reaction."

Sherlock frowned, then his eyes flew open when John presumed to reach across the table and scratch "Use a jade mortar and a basalt pestle to grind the Scarab beetles-more yield and more power."

Sherlock flushed, glaring at John who laughed behind his scarred hand, and the rest of the lesson passed in the like. Sherlock paying more attention to John's annotations, and John reaching over to occasionally make a suggestion in his neat but nearly illegibly small marks.

When the period ended and everyone leaped to their feet, Sherlock turned to John, "A Gryffindor helping a Ravenclaw cheat? Now I've seen everything,"

John rolled his shoulder with a wince, then chuckled, "Aww, Sherr, don't think of it like that, think of it as… a friend saving another friend the time it would have taken them to figure it out on their own,"

Sherlock swallowed an unexpectedly pleased bubble of emotion. He'd never had a friend before, and hearing the older boy say that meant a great deal to him, "B-but I don't have friends,"

Sherlock missed the flash of hurt in John's eyes, but even students hurrying out of the dungeon felt the sudden chill in the air around the two boys.

"Oh. Well, in that case, I'm sorry for… being a, a nuisance. I won't inflict myself on you anymore," John grabbed his backpack and marched angrily out of the classroom, leaving Sherlock standing cold-cocked in confusion.

'No!' his mind wailed, 'That isn't what I meant!'

But John was gone, already swallowed up by the throng of students.


End file.
